package utils

import (
	"strings"
	"github.com/disintegration/imaging"
	"path/filepath"
	"crypto/md5"
	"fmt"
	"bytes"
	"crypto/rand"
	"encoding/base64"
	"encoding/binary"
	"os"
	"time"
	"strconv"
	
	"github.com/fgrid/uuid"
)


type short uint16

var table = []short{
	0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241,
	0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440,
	0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40,
	0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841,
	0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40,
	0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41,
	0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641,
	0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040,
	0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240,
	0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441,
	0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41,
	0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840,
	0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41,
	0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40,
	0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640,
	0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041,
	0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240,
	0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441,
	0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41,
	0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840,
	0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41,
	0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40,
	0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640,
	0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041,
	0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241,
	0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440,
	0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40,
	0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841,
	0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40,
	0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41,
	0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641,
	0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040,
}

func CaculateCRC16(msg []byte) short {

	var crc short
	crc = 0x0000
	for _, b := range msg {
		crc = (crc >> 8) ^ table[(byte(crc)^b)&0xff]
	}
	return crc
}

/* CRC polynomial 0xedb88320 */
var crc32tab = []uint32{0x00000000, 0x77073096, 0xee0e612c,
	0x990951ba, 0x076dc419, 0x706af48f,
	0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988,
	0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2,
	0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
	0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
	0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172,
	0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c,
	0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
	0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423,
	0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
	0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106,
	0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
	0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d,
	0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e,
	0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
	0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
	0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7,
	0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0,
	0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa,
	0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
	0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81,
	0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a,
	0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84,
	0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
	0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
	0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc,
	0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e,
	0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
	0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55,
	0x316e8eef, 0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
	0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe, 0xb2bd0b28,
	0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
	0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f,
	0x72076785, 0x05005713, 0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38,
	0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
	0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
	0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69,
	0x616bffd3, 0x166ccf45, 0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2,
	0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc,
	0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
	0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693,
	0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94,
	0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d}

func CreateCRC32(databuf []byte, length uint32) uint32 {

	var crc uint32
	crc = 0xffffffff
	for _, b := range databuf {
		crc = (crc >> 8) ^ crc32tab[(byte(crc)^b)&0xff]
	}

	// flip bits
	crc = crc ^ 0xffffffff

	return crc

}

func AddCRC32(databuf []byte, length uint32) bool {

	var dwCrc32 uint32

	dwCrc32 = CreateCRC32(databuf, length)

	buf := new(bytes.Buffer)
	err := binary.Write(buf, binary.LittleEndian, dwCrc32)

	if err != nil {
		fmt.Fprintf(os.Stderr, "can not add CRC32.\n")
		return false
	}
	buff := buf.Bytes()
	databuf[length] = buff[0]
	databuf[length+1] = buff[1]
	databuf[length+2] = buff[2]
	databuf[length+3] = buff[3]

	return true
}

func CheckCRC32(databuf []byte, length uint32) bool {

	var dwCrc32, oldcrc32 uint32

	var dwOldCrc32 [4]byte

	dwCrc32 = CreateCRC32(databuf, length-4)

	dwOldCrc32[0] = databuf[length-3]
	dwOldCrc32[1] = databuf[length-2]
	dwOldCrc32[2] = databuf[length-1]
	dwOldCrc32[3] = databuf[length]

	crc32 := dwOldCrc32[0:4]

	buf := bytes.NewReader(crc32)

	err := binary.Read(buf, binary.LittleEndian, &oldcrc32)

	if err != nil {
		fmt.Fprintf(os.Stderr, "can not check CRC32.\n")
		return false

	}

	if dwCrc32 == oldcrc32 {
		return true
	} else {
		return false
	}
}


func ParseTagOption(str string) map[string]string {
	tags := strings.Split(str, ";")
	setting := map[string]string{}
	for _, value := range tags {
		v := strings.Split(value, ":")
		k := strings.TrimSpace(strings.ToUpper(v[0]))
		if len(v) == 2 {
			setting[k] = v[1]
		} else {
			setting[k] = k
		}
	}
	return setting
}



func GetImageFormat(url string) (*imaging.Format, error) {
	formats := map[string]imaging.Format{
		".jpg":  imaging.JPEG,
		".jpeg": imaging.JPEG,
		".png":  imaging.PNG,
		".tif":  imaging.TIFF,
		".tiff": imaging.TIFF,
		".bmp":  imaging.BMP,
		".gif":  imaging.GIF,
	}

	ext := strings.ToLower(filepath.Ext(url))
	if f, ok := formats[ext]; ok {
		return &f, nil
	} else {
		return nil, imaging.ErrUnsupportedFormat
	}
}

func CheckMD5Passwd( md5pwd string,orgpwd string )(isequal bool,pwd string ) {

	m5 := md5.Sum([]byte(orgpwd))
	
	str := fmt.Sprintf("%02x", m5)
	
	fmt.Printf("[util](CheckMD5Passwd):str=%s\n",str)
	
	if str == strings.ToLower(md5pwd) {
		isequal = true
		pwd = orgpwd
	}else{
		isequal = false
		pwd = ""
	}
	
	return isequal,pwd
}

func CheckMD5Passwd2( md5pwd string,orgpwdmd5 string )(isequal bool,pwd string ) {

	//m5 := md5.Sum([]byte(orgpwd))
	
	//str := fmt.Sprintf("%02x", m5)
	
	ss := strings.Split(orgpwdmd5,"|")
	if len(ss)<2 {
		return false,""
	} 
	
	str := strings.ToLower(ss[1])
	orgpwd := ss[0]
	
	fmt.Printf("[util](CheckMD5Passwd):str=%s\n",str)
	
	if str == strings.ToLower(md5pwd) {
		isequal = true
		pwd = orgpwd
	}else{
		isequal = false
		pwd = ""
	}
	
	return isequal,pwd
}


func Get3DESKeys() string {
	c := 18
	b := make([]byte, c)
	_, err := rand.Read(b)
	if err != nil {
		fmt.Println("error:", err)
		return ""
	}

	buf := new(bytes.Buffer)
	encoder := base64.NewEncoder(base64.StdEncoding, buf)
	encoder.Write(b)
	encoder.Close()

	str := string(buf.Bytes())
	return str
}

func CreateSessionID() string{
	c := 8
	b := make([]byte, c)
	_, err := rand.Read(b)
	if err != nil {
		fmt.Println("error:", err)
		return ""
	}
	m5 := md5.Sum(b)
	bf := new(bytes.Buffer)

	fmt.Fprintf(bf, "%02x", m5)

	str := string(bf.Bytes()[0:])
	
	return string(str)
}

func CreateTokenID() (int64,string){
	
	id := CreateContextID()
	
	cid := strconv.FormatInt(id,10)
	
	return  id,cid
}

func CreateContextID() int64 {
	
	t := time.Now()
	
	//id :=t.UnixNano()
	id :=t.Unix()
	
	return id 
}

func GetTimeFormat(layout string) string {
	t := time.Now()

	ye := t.Format(layout)

	
	return ye
}

func GetUTCTimeFormat(layout string) string{
	t := time.Now()

	ti := t.UTC()
	ye := ti.Format(layout)
		
	return ye
	
}

//return minutes
func CompareTime(t1 string,layout string) int {
	
	location,err := time.LoadLocation("Local")
	
	
	t,err := time.ParseInLocation(layout,t1,location)
	
	if err != nil {
		return 0
	}
	
	tt := time.Now()
	
	sec1 := t.Unix()
	sec2 := tt.Unix()
	
	return int((sec2-sec1)/60)
}


func BytesToFloat32(buf []byte) float32 {

	var h float32
	if len(buf)<4 {
		return 0.0
	}
	
	b := make([]byte,4)
	b[0]=buf[3]
	b[1]=buf[2]
	b[2]=buf[1]
	b[3]=buf[0]
	
	bb := bytes.NewReader(b)
	binary.Read(bb, binary.BigEndian, &h)
	
	return h
}

func CreateTokenString(namespace string) (token string) {
	
	us := uuid.NewNamespaceUUID(namespace)
	
	_,tid := CreateTokenID()
	
	token = namespace+"_"+ tid + us.String()
	
	return token
}


/*
	获取某个月份的开始日期和结束日期
	month ：0 获取本月的开始和结束日期
	month ： -1 获取上一个月的
	month ： 1 获取下一个月的日期
*/
func GetStartEndTimeOfMonth(month int)(start ,end string){
	nt := time.Now()

	nt = nt.AddDate(0,month,0)

	y,m,d := nt.Date()

	start  = fmt.Sprintf("%d-%02d-01 00:00:00",y,m)

	switch m {
	case 1,3,5,7,8,10,12:
		d = 31
	case 4,6,9,11:
		d = 30
	case 2:
		if y % 4 == 0 && y % 100 != 0 || y % 400 ==0 {
			d = 29
		}else {
			d = 28
		}

	}
	end  = fmt.Sprintf("%d-%02d-%02d 23:59:59",y,m,d)

	return
}

/*
	获取某个月份的开始日期和结束日期
	month ：0 获取本月的开始和结束日期
	month ： -1 获取上一个月的
	month ： 1 获取下一个月的日期
*/
func GetStartEndTimeOfMonthday(month int,day int)(start ,end string){
	nt := time.Now()

	nt = nt.AddDate(0,month,0)

	y,m,_ := nt.Date()

	start  = fmt.Sprintf("%d-%02d-%02d 00:00:00",y,m,day)

	end  = fmt.Sprintf("%d-%02d-%02d 23:59:59",y,m,day)

	return start,end
}


/*
	获取某个月份的开始日期和结束日期
	week ：0 获取本周的开始和结束日期
	week ： -1 获取上一周的
	week ： 1 获取下一周的日期
*/
func GetStartEndTimeOfWeek(week int)(start ,end string){

	nt := time.Now().Weekday()

	if nt == 0 {
		nt = 7
	}

	st := time.Now().Add(-time.Duration(nt-1)*24*time.Hour)

	y,m,d := st.Date()

	start  = fmt.Sprintf("%d-%02d-%02d 00:00:00",y,m,d)

	et := time.Now().Add(time.Duration(7-nt)*24*time.Hour)

	y1,m1,d1 := et.Date()

	end  = fmt.Sprintf("%d-%02d-%02d 23:59:59",y1,m1,d1)

	return start,end
}


/*
	获取某个月份的开始日期和结束日期
	week ：0 获取本周的开始和结束日期
	week ： -1 获取上一周的
	week ： 1 获取下一周的日期
	weekday : 一周的周几，从0-6，0代表周一
*/
func GetStartEndTimeOfWeekday(week int,weekday int)(start ,end string){

	nt := time.Now().Weekday()

	if nt == 0 {
		nt = 7
	}


	et := time.Now().Add(time.Duration(weekday-int(nt))*24*time.Hour)

	y1,m1,d1 := et.Date()
	start = fmt.Sprintf("%d-%02d-%02d 00:00:00",y1,m1,d1)
	end  = fmt.Sprintf("%d-%02d-%02d 23:59:59",y1,m1,d1)

	return start,end
}

